Pocket Medicine

PULMONARYQ

PULMONARY FUNCTION TESTS (PFTs)

• Spirometry: evaluate for obstructive disease

Flow-volume loops: diagnose and/or localize obstruction

Bronchodilator: indicated if obstruction at baseline or asthma clinically suspected

Methacholine challenge: helps dx asthma if spirometry nl, >20% ↓ FEV₁ → asthma

• Lung volumes: evaluate for hyperinflation or restrictive disease including NM causes

• D_LCO: evaluates functional surface area for gas exchange; helps differentiate causes of obstructive and restrictive diseases and screens for vascular disease & early ILD

Figure 2-1 Approach to abnormal PFTs